Naturalism and Morality

The naturalistic approach to morality requires that the existence of morality, and the ability of humans to be moral, must be compatible with scientific knowledge about humans and nature. Supernaturalistic approaches to morality make the rival claim that supernatural explanations are required for explaining the existence of morality and the ability of humans to be moral.

Is the supernatural necessary for morality? There are four primary arguments for a necessary connection between religion and morality.

Monotheistic religions, such as Christianity and Islam, appeal to all four arguments: unless God existed there could be no moral truths, and no way for humans to learn or care about moral truths, and only God could create humans with souls that permit them to be moral agents. The four arguments discussed here can be developed in many sophisticated ways, and variations on these arguments are numerous. You can visit websites about "Moral Arguments for the Existence of God" and "Religion and Morality".

The naturalist rejects the validity of supernatural explanations for morality, and offers naturalistic accounts of morality, as explored below. The ethical theory and specific ethical principles justifiable by naturalism are explored by "Naturalism and Secular Ethics". You can also consult another website on "Moral Naturalism".

Let's look more closely at these four arguments, beginning with "The truth of moral rules requires the existence of a supernatural reality to explain their truth." Consider the following argument:

Premise 3 is probably true because there is nothing permanent about human beings (their bodies and minds keep changing) or human societies (they gradually change their moral standards over time) or human life on earth (survival strategies of the human species gradually change over time) or wider nature (which is always changing). Since it is very difficult to see how something that can change can be responsible for something universal and eternal, this argument suggests that we have to look beyond humans, human societies, and nature itself to explain absolute moral truths.

Naturalists usually do not believe in the existence of absolute moral truths, holding that their existence has not been sufficiently established by either experience, reason, or science. Many religious people very much want to believe premise 1, and do believe premise 1, and feel very afraid of a world in which lots of people do not believe premise one, but these facts cannot prove the existence of absolute moral truths. Furthermore, finding any substantive moral rule that most religious people believe, or even a substantive moral rule that most people in the same religion really believe and consistently live by, is a very difficult task. Consider how all religions have modified their moral rules over the centuries, and how they have all broken apart into sects and denominations, precisely because they cannot agree on serious moral principles. Religion is a poor place to go looking for allegedly universal and eternal moral truths.

A few naturalists have accepted the truth of premises 1 and 2, and have tried to defend absolute moral truths by appealing to pure reason to justify absolute moral truths. However, the principles of pure reason had better be absolutely true also, and then the naturalist has to explain the absolute truths of pure reason (which leads to either having to consider a priori principles alien to scientific method, or leads right back to a supernatural reality to explain those truths). It is far easier for the naturalist to treat morality as a type of practical reliable knowledge, and far easier to explain relative moral truths (truths that do depend on human beings, or human societies, or wider nature), so naturalism is most compatible with moral relativism.

Most naturalists accept the truth of premises 2 and 3, and hold that premise 1 is false. Some naturalists have denied the truth of both premises 1 and 2, holding that claims to moral truth are only expressions of conviction or emotion that lack genuine cognitive status. If premise 2 is false, then moral judgments are not instances of any sort of knowledge, even practical reliable knowledge. The physicalist naturalism which says that reality only consists of what science knows about (option 6 explained at "Naturalism and Science") is most incompatible with the existence of moral truths because science's description of nature does not include things like moral values, moral rules, or moral ideals. Of course, the sciences can offer explanations of why people make moral judgments and why people believe moral principles, but the sciences are not designed to explain why moral truths are true. Physicalists are tempted to conclude that there aren't really any moral truths. You can read about "Emotivism" and the debate between "Moral Cognitivism vs. Non-Cognitivism". There are many difficulties with moral non-cognitivism. First, people are quite proficient at giving reasoned arguments for what is right and wrong, what should be done or not done, and what makes a person morally praiseworthy or blameworthy. People use morality as a body of common practical knowledge, despite frequent disagreement, and they appeal to this body of common knowledge to debate about their disagreements. If non-cognitivism were correct, the non-cognitivist would not expect other non-cognitivists to be interested in arguing over morality -- in a non-cognitivist world, if you were treated badly or unfairly you could complain, but you could not expect anyone to persuaded by your reasons why you should not be treated badly or unfairly. Some non-naturalists argue that since no one would really want to live in that sort of non-cognitive world, and real people actually do have some practical reliable knowledge about morality, then physicalism must be false. This is a hasty conclusion, though, since practical reliable knowledge is not incompatible with physicalism (morality may consists of recommended prescriptions for achieving certain goals, similar to the way that agriculture is composed of recommended prescriptions for growing crops). Furthermore, morality as practical reliable knowledge would be the sort of knowledge that can be improved by inquiry: something like the scientific method can propose and test hypotheses for improving the moral life. Science and morality need not be opposed to each other.

Some philosophers have argued that it is impossible for science to help explain any moral truths, relative or absolute. This position leads to "Moral Non-Naturalism": moral rules and values cannot be explained or justified solely in terms of any natural realities or truths. Moral facts cannot be found among the facts that science discovers, and moral facts cannot be justified from the truths that science discovers. However, this position only follows if it is the case that the only kind of knowledge is scientific knowledge, and ignores the possibility that morality is also a type of practical reliable knowledge. Morality is not the sort of thing to be justified by arguments that only have scientific textbook facts as premises, as if moral rules could be inferred from facts about water or neurons or gravity. Rather, morality can be justified by arguments that have practical activities of human beings as premises, so that moral rules could be inferred as practical tools for achieving these activities. Of course, the practical activities of human beings are quite natural, and can be studied and explained by natural methods. Sometimes philosophers worry that the practical activities of humans themselves need justification, and unless this can be accomplished, morality has no justification. For example, unless pursuing happiness can be morally justified, no moral rule that promotes human happiness can be justified. This leads to a regress problem: if every moral conclusion requires at least one moral premise, then there must be at least one moral premise that does not itself need justification. How could we know such a foundational moral premise? Perhaps by intuition or instinct? These worries that morality can never be known or ultimately justified can lead to "Moral Skepticism". However, the naturalist need not be a skeptic about morality. The naturalist can avoid the regress problem by denying that every moral conclusion requires at least one moral premise. Here is an analogy: an aesthetic conclusion can follow from premises that aren't themselves aesthetic. Consider the following argument:

By analogy, a moral conclusion can follow from premises that aren't themselves moral. Consider the following argument:

Some philosophers, of course, cannot resist asking for prior justifications for why people should want to sustain friendships, as if people shouldn't bother with friendships unless they could be sure that such goals were morally justifiable. The naturalist moral relativist does not search for such ultimate moral justifications (do people really need justifications for trying to live well, for trying to achieve satisfying aims, etc.?). The naturalist moral relativist is content to regard morality as a natural human activity. Of course, particular moral rules do try to tell us which ways of living are more worthy than other ways, and which sorts of satisfactions are more morally worthy than others. Moral relativism helps the naturalist explain why there are diverse and contradictory moral rules, whereas the extreme plurality of moral rules is a serious problem for the moral absolutist to explain.

The naturalist moral relativist can use any combination of these four ways of explaining the truth of moral rules, without needing to postulate the existence of a supernatural reality. You can read more about "Moral Relativism", "Moral Realism" and "Moral Epistemology".

Does the success of humans to be moral require the existence of a supernatural being to communicate moral knowledge to humans? Consider the following argument:

The naturalist agrees with premise 2, since moral relativism best explains how people learn moral truths. However, the naturalist rejects premise 1 or premise 3, or both. Premise 1 is false because morality is a kind of practical reliable knowledge. Morality's rules, values, and ideals can serve quite well to guide a person's conduct, even though this person does not know whether the morality she follows is universally or eternally true. So long as a person believes that their morality is justified, regardless of whether this morality is justified for everyone else too, a person can be genuinely moral. Some philosophers and theologians have worried that a morality cannot be well justified unless it could be well justified for all persons at all times. This worry is grounded in a fear of relativism: maybe if people see that their morality is relative, then they can never be assured that their own morality is correct, and then they would have to admit that they cannot know that their own morality is justifiable. Without a justifiable morality, there isn't enough reason to be moral, and a person might as well be as immoral as they please! This fearful worry that if different people can know different moralities, then no really knows any morality, is an invalid argument. It is invalid because it tacitly relies on a key unstated premise: a person must feel absolutely certain about a moral truth to know it and live it. Many religions cultivate and take advantage of some people's strange need for moral conviction: such people crave the feeling of certainty that their morality is the only true morality. Of course, the numerous religions which all offer satisfactions for moral cravings manage to offer a wide variety of moral rules and values, only contributing to the ample evidence of moral relativism. If the world's religions did somehow agree on most of their substantial moral rules and values, which they do not, then morality would be more practical and reliable, but hardly reach perfect knowledge.

Premise 3 is false for the naturalist because there really are no absolute moral truths to be known by anyone. But even the religious believer who thinks there are absolute moral truths should doubt premise 3. How does God know absolute moral truths? Either (a) the truth of absolute moral truths does not depend on God's existence, or (b) these truths do depend on God. If option (a) is chosen, then a significant argument for God (the first argument examined on this webpage, above) is set aside and it becomes much more difficult for the supernaturalist to account for absolute moral truths. The supernaturalist would have to postulate a separate and independent supernatural reality, just as eternal and unchanging as God, to explain the truth of absolute moral truths. Monotheistic religions such as Christianity, Judaism, and Islam reject anything supernatural that does not depend on God.

So option (b) seems preferable to the supernaturalist. However, the idea that absolute moral truths depend on God suffers from a major difficulty. In Plato's Euthyphro, the Euthyphro dilemma is presented: Is something moral because God declares it to be moral, or does God declare something moral because it is moral? Option (b) says that something is moral because God willfully declares it to be moral. This is the "Divine Command Theory of Ethics" and you can read about "Theological Voluntarism". The religious follower who selects option (b) must admit that if God commands that murdering innocent children is morally required, then murdering innocent children is moral. The religious follower cannot judge whether God has any sufficient reason to command that murdering innocent children is wrong, since right and wrong simply depend on God's decision. God does not make the murder of innocent children wrong because God knows that it is wrong [justifying this claim requires option (a)]. This religious follower must therefore admit that neither she nor anyone else can figure out whether God has any reasons for commanding certain things to be moral or immoral, or why God might sometime change what is moral. [Option (b) cannot be rescued by claiming that God commands true morality because God essentially is morally good, because justifying this claim requires option (a)]. The religious follower has been driven to the conclusion that, for all anyone knows, God cannot know absolute moral truths, and hence premise 3 cannot be known to be true. According to the Divine Command Theory, the only reason a religious follower has for obeying a moral rule is that God has commanded it. On this theory, the religious follower has no rational way to judge moral commandments from God -- the religious follower in effect abandons all independent moral judgment when obeying God. Option (a) was far better in this regard -- by holding that moral truth was independent from, this idea at least opened up the possibility that people could judge moral truth for themselves (and people would not need God to do this). This major difference between option (a) and option (b) inspires the naturalist to formulate an argument from morality against the Divine Command Theory:

If the Divine Command Theory should be abandoned by religious people, then the existence of absolute moral truths might still be rescued by trying to postulate a separate supernatural reality, apart from God, to explain absolute moral truths. Monotheists would likely resist this option, but let's explore it further. Suppose this option is correct -- the next question is whether people can learn about these absolute moral truths by themselves, or still need God to consult morality and them instruct people. If people can't learn absolute moral truths by themselves, they are entirely dependent on God's instruction. But that complete dependence on God would put people in the same ignorant position as the Divine Command Theory, and erect the same obstacle to people being responsible agents, by the argument just considered. The alternative, which supports people being responsible moral agents, is to suppose that people have some way of learning absolute moral truths by themselves without God's help (for example, perhaps by the use of reason). On this option, God is not needed for morality.

The naturalist can conclude that the success of humans to be moral does not require the existence of a supernatural being to communicate moral knowledge to humans. Either no absolute moral truths really exist, so nothing supernatural needs to be postulated, or absolute moral truths can be learned by responsible moral agents without God's assistance. The naturalist accepts the first and simpler explanation that all moral truths are relative.

Does the motivation for humans to behave morally depend upon their conviction that a supernatural being guarantees that moral conduct is not ultimately meaningless or without value? Consider the following argument:

Naturalists agree with premises 3 and 4 of this argument from "Moral Motivation," and they cannot understand why monotheists view naturalism as an obstacle to people wanting to behave morally. Naturalists behave about as morally as anyone else (for example, the percentage of criminals who are atheists is just about the same as the percentage of atheists in the general population). Of course, the faithful see naturalists rejecting their God and his/her/its commands, and if they feel that the only motivation to be moral is to fear/love/respect/patronize/appease their God, then the naturalist must seem morally unmotivated. But this failure to understand how the naturalist is motivated to be moral is predicated on the assumption that God exists, so it cannot help justify the existence of God. The faithful may believe that they need God to be morally motivated, but this (sad) fact about them cannot be used to argue for God's existence.

Naturalists cannot prove that premise 1 is false, but it is reasonable to be skeptical. Many of the world's non-monotheistic supernaturalisms are designed to guarantee the ultimate supremacy of moral goodness. Even if premises 2-4 are true, this argument cannot support monotheism.

Naturalists reject premise 2. The faithful who accept premise 2 worry that a moral action is meaningless unless its positive value is eternally guaranteed. This worry is analogous to the worry that the eventual destruction of something we create makes our creation ultimately meaningless and valueless. This is the existential worry of nihilism: everything might really be pointless. What will our lives and our deeds really mean, one million years from now, or when the universe ends? Naturalists are not immune from this worry. Some naturalists do believe that human life and all human creations are ultimately meaningless and valueless when imaginatively viewed from any sufficiently remote perspective. A few philosophies and religions instruct us to adopt this nihilistic stance towards our lives, our deeds, and our creations: we should stoically view them as having little or no value, so that we are not attached to them and we suffer nothing when they are gone. Even if naturalism required nihilism, nihilism does not make moral conduct unreasonable and need not deprive us of the motivation to be moral. First of all, nihilism cannot imply that a person would only do immoral things. The religious person worries, Without God, why should I bother being moral? Of course, if nihilism were correct and all of my deeds are ultimately meaningless, then my bad deeds are meaningless too -- Why should I bother being immoral either? Nihilism cannot imply anything about what a person should or would do.

Premise 3 is likely true. Naturalism can explain how moral conduct is meaningful, so there are naturalistic ways to show how people can be reasonably motivated to be moral. Naturalism has no way of showing how to ensure that people are always moral (religion has no way of ensuring moral conduct either, notoriously). Other motivations constantly compete with the motivation to be moral, and will often overpower moral motivation, regardless of whether one is a naturalist or a supernaturalist. Premise 3 only asks that the motivation to be moral, however it stands up against rival motivations, at least be reasonable if not dominant or determinative. And there are naturalistic explanations for the reasonableness of preferring moral conduct over immoral conduct. Naturalists view morality as a kind of practical reliable knowledge, having several sources. Recalling the kinds of relativism explored in section one, moral knowledge can come from personal reflection, cultural heritage, and the struggle for survival. The naturalist can argue that (1) possessing moral knowledge alone provides a reasonable motivation to be moral; (2) moral conduct can be intrinsically satisfying for one's self and hence is reasonable; (3) moral conduct towards another person is valuable to that person and hence reasonably creates value; (4) moral conduct can be a practical means of maintaining beneficial social relations and hence is reasonable; (5) moral conduct can be useful for survival and hence would be reasonable. Any one of these options suffices to supply a naturalistic account of reasonable moral motivations; the naturalist would assemble several of the more plausible options in order to organize a robust alternative to supernaturalism.

The naturalist can finally point out that moral motivation, moral courage, and moral character hardly depend on an assurance that "all will work out for the best in the end." Why should religious faith in ultimate victory deliver moral superiority? After all, who deserves higher approval -- the person who does the right thing when the best outcome is already guaranteed, or the person who does the right thing even when the outcome appears hopeless? Righteousness even in the face of despair marks the genuinely moral person. Such a person is not unreasonable for their convictions. Supernaturalism can inspire people to be moral, it is undeniable. But this argument from "Moral Motivation" does no justice to religious inspiration, and The naturalist may not know how it all will turn out, but the naturalist can reasonably want morality to prevail right here and now. Helping the needy, promoting peace, and protecting the weak are always morally meaningful, regardless of what may happen tomorrow.

Does the capacity for humans to be responsible moral agents require that humans possess some supernatural property or be partly supernatural. Consider the following argument:

Naturalists accept this entire argument and agree with its conclusion. Naturalists agree with premise 2, which follows from naturalistic determinism: all events are completely controlled by natural causes. You can read more about "Causal Determinism". Naturalists do not believe in the existence of this sort of "free will" -- what is termed "contra-causal freedom" -- and claim that a person can be a responsible moral agent even if this person lacks this "free will". You can read more about "Free Will". Supernaturalists go on to provide an additional argument attempting to show that people possess some supernatural property or be partly supernatural. This argument usually proceeds as follows:

The naturalist who accepts premise 1 must reject premise 2. Why should anyone think that premise 2 is correct? There are three primary reasons offered in support of premise 2. First, we experience our intentional decisions as making a new difference to the world -- when we are trying to make a tough decision between doing A or doing B, it briefly feels like both A or B could really happen, depending on that decision. During the deciding process, we believe that the entire universe up to the moment of decision could result in A, and we also believe that the entire universe up to the moment of decision could result in B instead. If we instead believe that the entire universe up to that moment completely controls the decision for one of the options (the view of naturalism), then we would not believe that we are really making a decision, and it wouldn't feel like we are really making a decision. Since we know that we do make decisions like this example, then we know we have free will. You can read more about "Fatalism". The naturalist's reply is that this "knowledge" could just be an emotional or cognitive illusion. Second, our culture expects us to be responsible moral agents with free will. For example, our legal system is grounded on the principle that a person cannot be held responsible for some action A if it is demonstrated that circumstances determined that this person necessarily had to do A. If naturalism is correct, however, then circumstances always completely determine all actions of people -- every event, every action, is the necessary outcome of the universe's processes up to the moment of action. Civilized culture requires us to fully believe that we can be responsible moral agents, and so we know that we have free will. The naturalist's reply is that the social usefulness of a cultural dogma does not prove anything about reality. Third, religious faith instructs us that we have free will, so we know that we have free will. The naturalist's reply is that this tactic just begs the question -- why should we believe supernatural religion in the first place?

Interestingly, a theistic God (a personal God that is all-knowing, all-powerful, and all-good) would get caught in paradoxical contradictions upon trying to give humans free will. The sort of free will that non-naturalists really desire turns out to be the sort of free will that would permit a creature to surprise God, but a theistic God can never be surprised. You can read about "Foreknowledge and Free Will".

The naturalist does not accept the existence of contra-causal free will, yet believes that many people are quite capable of being responsible moral agents. How does the naturalist explain moral agency in a way that is compatible with science? A free will sufficient for moral agency only requires that a creature have both (a) partial control over current habits, and (b) partial control over the deliberate modification of habits. This partial control is not any sort of contra-causal free will, but rather recognizes humans as energetic causes in their own right, alongside environing causes. Where people have both (a) and (b) we rightly hold them morally responsible and use reward and punishment accordingly [reasonable rewards and punishments would be designed to increase (a) and (b) over time].

Not all naturalists believe that people have (a) partial control over current habits, and (b) partial control over the deliberate modification of habits. Some naturalists over-emphasize "hard determinism" by tracing everything a person is capable of doing back through causal processes that eventually come from the outside environment and pre-date that person's existence, and then happily deny that humans ever really control any of their conduct. The false premise to both sides, common to defenders of contra-causal free will and defenders of hard determinism, is the notion that "unless a person can have control over ultimate causes for their conduct, that human lacks full responsibility". Why is this premise false? When a person does have free will over a choice C, that is not because that person could also have not done C given all the same conditions at that moment (internal plus external causal processes), but rather because that person could also have not done C given all the same external conditions at that moment. If, in a given situation, a person could do C and also not do C, given all the same external conditions at that moment, this explains why this person rightly feels that their own internal decision process controls the outcome, and also explains how culture can assign responsibility for decisions over which we have control. We hold a person responsible for an action because we conclude after inquiry that this action probably wouldn't have occurred given only all the same external casual conditions at the time of the action -- isolating by subtraction this person as the "cause" of that action. The fact that this person could not possibly have performed that action without the cooperation of many external causal processes in the PAST is quite irrelevant to assigning responsibility (but quite relevant to the different question of whether we additionally will praise or blame this person, reward or punish this person, for this action).